A suspected case of foot-and-mouth has been found at a farm at Hawnby near Thirsk, north Yorkshire, the Department of the Environment, Food and Rural Affairs said tonight.

Livestock movements in a five mile radius around the farm have been banned as a precaution after suspect lesions were found in the mouths of two sheep during an inspection visit, a spokesman added.

Animal Welfare Minister Elliot Morley said tonight: "It is too early to say if this will be the first case of the disease since last September. The laboratory tests - which can take between four and 96 hours - will need to be completed first."

The farm was affected by the outbreak last August when livestock were slaughtered as part of the contiguous cull.

The sheep discovered with the suspected lesions today were being examined as part of an inspection visit required by Defra when farms restock after foot-and-mouth.

Samples were taken from the animals for urgent testing at the Institute of Animal Health laboratory at Pirbright, Surrey, a Defra spokesman added.

The two sheep were being slaughtered as a precaution.

Mr Morley added: "We must take no chances with this very infectious disease. The Department thoroughly investigates all suspect cases, precautionary measures are put in place and we stand ready to take immediate action if the tests show positive.

"This suspect case underlines the need for farmers and vets to remain vigilant during the restocking period and during the lambing season, and to maintain high standards of biosecurity."

A Defra spokesman said the suspect farm at Hawnby had been sealed off and officials were tracing all farms which had supplied sheep to the premises. These would be placed under restriction and inspected.